The definitive thing to say when you don't want to hear somebody speak anymore. Usually accompanied by a clasping of the hands over the ears in a mature and composed fashion to signify that you are done with the conversation. Short intakes of air inbetween scores of "lalala" should be expected and has been scientifically proven to increase dramatic effect and frustrate the antagonizing speaker to habitual silence.

Person 1 "Rent was due a week ago, you spent the money on Motley Crue reunion tickets, and why is there glitter everywhere? Tou seriously need to grow up. And another thing-"

Person 2 "Lalala"

Person 1 "What are you doing? I mean it, you can't use your money on drinking and leopard tights, it's-"